Abstract/Summary (Comparative Pathology Core?Core 4) The goal of the Comparative Pathology Core is to provide professional services and expertise to Center Investigators of the Cystic Fibrosis Research and Translation Core Center. To facilitate these goals the Pathology Core offers 1) technical expertise and support for histotechnology techniques from tissue processing to specialized staining (histochemical and immunohistochemical) and 2) ACVP-boarded veterinary pathologist expertise and support for morphologic, quantitative and semi-quantitative evaluation of tissues from CF pig, CF mouse and CF ferret studies. The Comparative Pathology Core will provide services to Center Investigators in a timely and efficient manner for optimal assessment of tissues. The goals of the Comparative Pathology Core are to: 1. Provide histotechnology services to the Center Investigators through CPL resources and experienced staff. 2. Assist with professional necropsy services for Center Investigators. 3. Provide veterinary pathologists services to the Center Investigators. 4. Serve as a conduit for dissemination of histologic specimens from CF pig and ferret models to researchers outside the University of Iowa.